Vehicles, such as aircraft, often include various devices on their external surfaces. Examples of such items include sensors, weapon mountings and cameras. Such externally projecting devices can have disadvantages in terms of reducing aerodynamics and increasing radar cross section (thereby making the aircraft less stealthy). External formations can be used by hostile parties to obtain a radar signature that can assist with identifying the aircraft. Conventional aircraft weapon bays have large doors that open outwardly to allow a weapon to be positioned outside the aircraft. Such apparatus is large and susceptible to being detected by radar.
Further, external real estate on particular types of vehicles may be limited and so it can be difficult to fit several external items.